Many trailers 2 are in use today which permit a motor vehicle to tow loads. Such trailers 2 include boat trailers as well as cargo carrying trailers. Trailers 2 generally comprise a load bearing trailer frame 4 mounted on a wheeled axle 6. Extending forwardly from trailer frame 4 is a coupler 8. Moving trailers 2 is accomplished by engaging coupler 8 on trailer 2 to a mating ball mount (not shown) on the motor vehicle. Often a jack stand 9 is optionally provided proximate to coupler 8 to allow a user to raise coupler 8 high enough to engage the ball mount on a motor vehicle. However, often times a user is desirous of moving trailers 2 manually for purposes of storing or moving from storage in areas where a motor vehicle cannot be employed.
Hand trucks are well known in the art as devices for movement of heavy objects such as appliances, boxes and the like. As best seen in FIG. 1, a typical hand truck 10 comprises a planar load bearing platform 12 which extends laterally outward from an elongated frame 14. An axle 16 supporting two wheels 18 is mounted at the point where platform 12 and frame 14 are joined. A user employs frame 14 as leverage to pivot truck 10 about axle 16 to lift loads (not shown) supported on platform 12. There are several adaptions whereby hand truck devices are used to move objects other than boxes and appliances. For example, trailer dollys provide a permanent ball mount for use with pulling trailers.
Other examples included U.S. Pat. No. 2,723,130 entitled "Wheeled Support for Outboard Motors" which issued on Nov. 8, 1955 to Andrews discloses a hand truck which may be used as a boat dolly. A stiffening bar 20, which supports a ball 28, is removably mounted. Sockets 22 and 24 are welded to support members 16 and 18. Stiffening bar 20 is received in these sockets. However, it should be noted that Andrews requires the permanent attachment of sockets to the hand truck in question.
U.S. Pat. No. 3,350,797 entitled "Set of Interchangeable Utility Apparatus" which issued on Nov. 7, 1967 to Dassinger et al. shows, in FIGS. 7-11, an attachment to a hand truck in which sleeves 80, 81 are slipped over tines 39, 40 for means of mounting the attachment.
U.S. Pat. No. 1,150,964 entitled "Hand Truck" which issued on Aug. 24, 1915 to Phelps is of more general interest in showing an extension platform 18 which may be attached to socket members 10.
None of the known prior art disclose the adaptor set forth herein.